doi:10.1093/ejcts/ezs233 Advance Access publication 24 May 2012 Reply to Sahni and Bhatia

We thank Sahni and Bhatia [1] for their careful analysis of our paper [2]. Due to a typographical error, the open diamond data in Figure 3b is indeed incorrectly labelled as being for 50 mm rather than 40 mm. We can confirm the underlying calculations and equations are correct for the concept and the data pre-sented in the figure. With regard to Figure 6, and the equation for height of impact (H), H = R × sin(90 – θ). Sahni and Bhatia [1] have misread the methodology text, as R refers to the radius of the aortic curva-ture of the ascending aorta, not the radius of the aorta. The radius of the aorta does not affect the height of impact of the ejected blood. The demonstration that the site of impact is non-physiological in some instances indicates that the direct jet impact may not always be the initiating pathological event for the aortic dissection. The angle nomenclature is 90 – θ to fit in with the angle nomenclature of the other figures in the manu-script. The equation and Figure 6 are thus correct. REFERENCES [1] Sahni S, Bhatia S. Ascending aortic curvature as an independent risk factor for aortic dissection: the mathematical model and underlying equa-tions. Eur J Cardiothorac Surg 2012;42:755. [2] Poullis MP, Warwick R, Oo A, Poole RJ. Ascending aortic curvature as a